The present invention relates to displacement, or position, sensors of the type having a movable element capable of being placed in contact with a component whose displacement is to be monitored, and particularly relates to displacement sensors constructed to monitor small amplitude displacements of the order of a fraction of an inch.
Displacement sensors of the type contemplated by the present invention are useful for a variety of purposes, one of which is the monitoring of movements experienced by parts of a structure for testing purposes.
The invention provides a displacement sensor for providing an indication of the position of a first body relative to a second body, the first body being displaceable relative to the second body in a displacement direction. The sensor comprises two magnets that are spaced from one another in the displacement direction to define therebetween a region containing a magnetic field, with a magnetic field sensing element mounted in the region. The sensor further comprises means for coupling at least one of the magnets to one of the bodies and the magnetic field sensing element to the other of the bodies to produce a relative displacement between the at least one magnet and the magnetic field sensing element in the displacement direction in response to displacement of the first body relative to the second body.